Sandwich-Like Co₃O₄/Graphene Nanocomposites as Anode Material for Lithium Ion Batteries.

In this work, sandwich-like Co₃O₄/graphene nanocomposites were synthesized by a facile hydrothermal process and subsequent thermal treatment. X-ray diffraction and scanning electron microscopy analyses were employed to characterize crystalline structural and morphology. Results demonstrated that approximately 150 nm Co₃O₄ particles were dispersed among the graphene sheets. The graphene not only enhanced the conductivity of Co₃O₄/graphene nanocomposites but also improved the structural stability of Co₃O₄ nanoparticles. As an anode material for lithium-ion batteries (LIBs), the Co₃O₄/graphene nanocomposites exhibited excellent electrochemical performance, higher rate capability, and longer cycle life than pristine Co₃O₄. The Co₃O₄/graphene nanocomposites maintained a specific capacity of 639.8 mAhg-1 at a current density of 0.5C (1C = 890 mAg-1) after 50 cycles with capacity retention rate of 71%. Co₃O₄/graphene nanocomposites also exhibited excellent rate performance with a discharge capacity of 676.5 mAh g-1 at a current density of 2C. Overall, the sandwich-like Co₃O₄/graphene nanocomposites are good candidate materials for high-capacity anode for LIBs.